Clean up hermes-engine Pod

Summary:
Aside from the log output, these changes do not change the behavior of the hermes-engine Pod.

Removed unused git branch checks.
Use react_native_path var to build filepaths.
Edit Hermes build from source log message to be consistent with other logs.

Changelog: [Internal]

Reviewed By: cipolleschi

Differential Revision: D39699165

fbshipit-source-id: 7e389eb5315fc5a2510b84eddac2f499a3e65157

sdks/hermes-engine/hermes-engine.podspec

@@ -4,22 +4,25 @@
 # LICENSE file in the root directory of this source tree.
 
 require "json"
-require "open3"
 
-# sdks/hermesc/osx-bin/ImportHermesc.cmake
-import_hermesc_file=File.join(__dir__, "..", "hermesc", "osx-bin", "ImportHermesc.cmake")
+module HermesHelper
+  BUILD_TYPE = :debug
+  # BUILD_TYPE = :release
+end
+
+react_native_path = File.join(__dir__, "..", "..")
 
 # package.json
-package_file = File.join(__dir__, "..", "..", "package.json")
+package_file = File.join(react_native_path, "package.json")
 package = JSON.parse(File.read(package_file))
 version = package['version']
+
+# sdks/.hermesversion
+hermestag_file = File.join(react_native_path, "sdks", ".hermesversion")
 isInCI = ENV['CI'] == true
-hermestag_file = File.join(__dir__, "..", ".hermesversion")
 
-# We need to check the current git branch/remote to verify if
-# we're on a React Native release branch to actually build Hermes.
-currentbranch, err = Open3.capture3("git rev-parse --abbrev-ref HEAD")
-currentremote, err = Open3.capture3("git config --get remote.origin.url")
+# sdks/hermesc/osx-bin/ImportHermesc.cmake
+import_hermesc_file=File.join(react_native_path, "sdks", "hermesc", "osx-bin", "ImportHermesc.cmake")
 
 source = {}
 git = "https://github.com/facebook/hermes.git"
@@ -28,7 +31,7 @@ if ENV.has_key?('HERMES_ENGINE_TARBALL_PATH')
   Pod::UI.puts '[Hermes] Using pre-built Hermes binaries from local path.' if Object.const_defined?("Pod::UI")
   source[:http] = "file://#{ENV['HERMES_ENGINE_TARBALL_PATH']}"
 elsif version == '1000.0.0'
-  Pod::UI.puts '[Hermes] Hermes needs to be compiled, installing hermes-engine may take a while...'.yellow if Object.const_defined?("Pod::UI")
+  Pod::UI.puts '[Hermes] Installing hermes-engine may take a while, building Hermes from source...'.yellow if Object.const_defined?("Pod::UI")
   source[:git] = git
   source[:commit] = `git ls-remote https://github.com/facebook/hermes main | cut -f 1`.strip
 elsif File.exists?(hermestag_file) && isInCI
@@ -40,18 +43,13 @@ else
   source[:http] = "https://github.com/facebook/react-native/releases/download/v#{version}/hermes-runtime-darwin-v#{version}.tar.gz"
 end
 
-module HermesHelper
-  BUILD_TYPE = :debug
-  # BUILD_TYPE = :release
-end
-
 Pod::Spec.new do |spec|
   spec.name        = "hermes-engine"
   spec.version     = version
   spec.summary     = "Hermes is a small and lightweight JavaScript engine optimized for running React Native."
   spec.description = "Hermes is a JavaScript engine optimized for fast start-up of React Native apps. It features ahead-of-time static optimization and compact bytecode."
   spec.homepage    = "https://hermesengine.dev"
-  spec.license     = package["license"]
+  spec.license     = package['license']
   spec.author      = "Facebook"
   spec.source      = source
   spec.platforms   = { :osx => "10.13", :ios => "12.4" }